Get rows within current month

Get the rows from a table filtered by current month in psql.

Example table –

+--------------+--------------------+--------------------------+
|    id        |     name           |    registeration_date    |
+--------------------------------------------------------------+
|    1         |     abc            | 2018|12|31 18:30:00|00   |
+--------------------------------------------------------------+
|    2         |     pqr            | 2018|11|31 18:30:00|00   |
+--------------------------------------------------------------+
|    3         |     lmn            | 2020|07|10 18:30:00|00   |
+--------------+--------------------+--------------------------+

After query result, assuming current month is July, 2020:

+--------------+--------------------+--------------------------+
|    id        |     name           |    registeration_date    |
+--------------+--------------------+--------------------------+
|    3         |     lmn            | 2020|07|10 18:30:00|00   |
+--------------+--------------------+--------------------------+

Answer

The usual approach is to use a range query to allow for an index usage on registration_date

select *
from the_table
where registration_date >= date_trunc('month', current_date) 
  and registration_date < date_trunc('month', current_date)  + interval '1 month';